As an operating lever device of the kind specified, the device described in Japanese Laid-Open Utility Model Application NO. SHO 62-140636 is known.
Briefly, as shown in FIGS. 1 and 2 the above-mentioned prior art includes an operating lever 2 which is mounted on the device body 1 by means of a universal coupling 3 so as to allow it to be tilted in either X direction or Y direction. The above-mentioned device body 1 is provided with a first pair of rotational angle sensors 4, 4 in the X direction and a second pair of rotational angle sensors 5, 5 in the Y direction. The rotating shafts of the first pair of rotational sensors 4, 4 being connected by means of a first gimbal 6, and the rotating shafts of the pair of second rotational angle sensors 5, 5 being operating lever 2 is disposed through elongated holes 6a and 7a formed in the first and second gimbals 6 and 7, respectively so that when the lever 2 is tilted, in the X direction the second gimbal 7 is pivoted so as to rotate the rotating shafts of the second pair of rotational angle sensors 5, 5, whilst when the lever 2 is tilted in the Y direction the first gimbal 6 is pivoted so as to rotate the rotating shafts of the first pair of rotational angle sensors 4, 4.
In the above-mentioned prior art operating lever device, if there is a clearance between the base portion 2a of the lever 2 and the elongated holes 6a, 7a of the first and second gimbals 6, 7, respectively, then the pivot amount of each of the first and second gimbals 6, 7 when the lever 2 is tilted does not correspond exactly to that of the lever 2 . Therefore it is necessary to hold the base portion 2a of the lever 2 constantly in contact with the elongated holes 6a and 7a, respectively. As a result, the base portion 2a of the lever 2 slides along either one of the elongated holes 6a and 7a of the first and second gimbals 6 and 7, respectively accordingly these sliding portions tend to wear down with the passing of time. When the sliding portions wear down, a clearance is created between the base portion 2a of the lever 2 and each of the elongated holes 6 and 7, so that the angle of inclination of the lever 2 cannot be detected precisely by means of the rotational angle sensors 4 and 5.
Further, the first and second gimbals 6 and 7 are each comprised of a thin-walled plate member which is bent substantially in a U-shape and which has a low rigidity. Therefore, when they are pivoted by the operating lever 2 they tend to flex in a manner wherein the angle of inclination of the operating lever 2 is not be transmitted accurately to the rotating shaft of each of the rotational angle sensors 4 and 5. This of course lowers the detection accuracy of the angle of inclination lever.
Further, since the first pair of rotational angle sensors 4, 4 in the X direction and the second pair of rotational angle sensors 5, 5 in the Y direction are mounted on the device body 1 while the rotating shafts 4a, 5a a thereof are connected to both ends of the first and second gimbals 6, 7, respectively, the first and second gimbals 6 and 7 are supported by their respective rotating shafts 4a and 5a so as to pivot freely. Therefore, it is difficult to locate each of the pairs of rotating shafts 4a, 4a, and 5a, 5a in alignment. If the accuracy of alignment is low, then the pivot centers of both ends of each of the gimbals 6 and 7 get out of alignment. Accordingly, of the gimbals 6, 7 cannot be swung smoothly and excessive forces are exerted thereon. Further when each of the gimbals 6, 7 is pivoted the angles of rotation of each of the pairs of rotating shafts 4a, 4a and 5a, 5a differ from one another, thereby lowering the detection accuracy of the angle of inclination of the operating lever 2.